#include "apue.h"

const int BUFFSIZE = 1;

int main() {
    int n;
    char buf[BUFFSIZE];

    while ((n = read(STDIN_FILENO, buf, BUFFSIZE)) > 0) {
        if (write(STDOUT_FILENO, buf, n) != n) 
            err_sys("write error");
    }

    if (n < 0)
        err_sys("read error");

    return 0;
}
